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  PUBLIC "-//OASIS//DTD DITA Composite//EN" "ditabase.dtd">
<topic id="CommandCenterDatabaseReference-memory_info">
   <title> memory_info </title>
   <body>
      <p>The <codeph>memory_info</codeph> view shows per-host memory information from the
            <codeph>system_history</codeph> and <codeph>segment_history</codeph> tables. This allows
         administrators to compare the total memory available on a segment host, total memory used
         on a segment host, and dynamic memory used by query processes.</p>
      <table>
         <tgroup cols="2">
            <thead>
               <row>
                  <entry>Column</entry>
                  <entry>Type</entry>
                  <entry>Description</entry>
               </row>
            </thead>
            <tbody>
               <row>
                  <entry>
                     <codeph>ctime</codeph>
                  </entry>
                  <entry>timestamp(0) without time zone</entry>
                  <entry>Time this row was created in the <codeph>segment_history</codeph>
                     table.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>hostname</codeph>
                  </entry>
                  <entry>varchar(64)</entry>
                  <entry>Segment or master hostname associated with these system memory
                     metrics.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>mem_total_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>Total system memory in MB for this segment host.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>mem_used_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>Total system memory used in MB for this segment host.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>mem_actual_used_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>Actual system memory used in MB for this segment host.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>mem_actual_free_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>Actual system memory free in MB for this segment host.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>swap_total_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>Total swap space in MB for this segment host.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>swap_used_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>Total swap space used in MB for this segment host.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>dynamic_memory_used_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>The amount of dynamic memory in MB allocated to query processes running on
                     this segment.</entry>
               </row>
               <row>
                  <entry>
                     <codeph>dynamic_memory_available_mb</codeph>
                  </entry>
                  <entry>numeric</entry>
                  <entry>The amount of additional dynamic memory (in MB) available to the query
                     processes running on this segment host. Note that this value is a sum of the
                     available memory for all segments on a host. Even though this value reports
                     available memory, it is possible that one or more segments on the host have
                     exceeded their memory limit.</entry>
               </row>
            </tbody>
         </tgroup>
      </table>
   </body>
</topic>
